BIOS firmware can boot a BIOS formatted /boot partition installed on a software RAID 1 pair no problem. It can even boot from a /boot installed on LVM volume that lives on a software RAID 1 pair.
But with a uEFI install, /boot/efi has to be on a non md partition or the firmware can not access it.
Is this a flaw with uEFI firmware? Or is the problem with how Ubuntu sets up /boot/efi on software RAID devices? Could it be a flaw with how GPT partition tables present software RAID to the firmware?
For reference, I’m using: Ubuntu Server 14.04.3 64bit mdadm RAID setup from the 'Manual' option in the partitioner.